The phenotypic description of velocardiofacial syndrome (VCFS) has evolved over the last 25 years and, in particular, since 1992 when the 22q11.2 deletion was identified as the cause of this diagnosis (Driscoll et al., 1992). In addition, we and others have described multiple clinical diagnoses which were originally described separately but are now known to be due to the 22q11.2 deletion. These include DiGeorge syndrome, the autosomal dominant form of Opitz G/BBB syndrome, Cayler Cardiofacial syndrome, and conotruncal anomaly face syndrome. Early reports of these syndromes often included anecdotal descriptions of the traits of clinically diagnosed patients. Our study has taken on the challenge of conducting comprehensive systemic evaluations of patients with the 22q11.2 deletion (McDonald-McGinn et al., 1999) in an effort to identify areas which were previously unrecognized in this population of patients and to, where possible, make inroads into genotype-phenotype correlations and mechanisms of the deletion.